Abstract: Employee #1 and two other employees were laying pipe in a trench that was 13-feet-deep. One employee was in the trench box, another employee was operating the Komatsu trackhoe (Model Number PC400 LC) and Employee #1 was the groundman. The trench box was 12 feet in height and was sticking out of the hole approximately five feet. The trench box was six feet off of the bottom of the trench. The trench was 30 feet long with a manhole box set at one end. Employee #1 was on the blind side of the trackhoe so the operator could not see him. As a piece of 24-inch RCP pipe was being lowered into the trench box, Employee #1 stepped onto the ledge of the box and stuck his head over the top of the box to speak with the employee inside the box. He was then struck in the head by the bucket of the trackhoe, and his head was pinned between the trackhoe bucket and the top edge of the trench box. When the bucket was moved, Employee #1 then fell, head down, between the embankment and the trench box, and struck his head on the ledge and side of the trench box before being wedged into the 12-inch space.